"""
"""
import traceback

from AnyQt.QtWidgets import QWidget, QPlainTextEdit, QVBoxLayout, QSizePolicy
from AnyQt.QtGui import QTextCursor, QTextCharFormat, QFont
from AnyQt.QtCore import Qt, QObject, QCoreApplication, QThread, QSize
from AnyQt.QtCore import pyqtSignal as Signal


class TerminalView(QPlainTextEdit):
    def __init__(self, *args, **kwargs):
        QPlainTextEdit.__init__(self, *args, **kwargs)
        self.setFrameStyle(QPlainTextEdit.NoFrame)
        self.setTextInteractionFlags(Qt.TextBrowserInteraction)
        self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
        self.setSizePolicy(QSizePolicy.Preferred, QSizePolicy.Preferred)

        font = self.font()
        font.setStyleHint(QFont.Monospace)
        font.setFamily("Monospace")
        self.setFont(font)

    def sizeHint(self):
        metrics = self.fontMetrics()
        width = metrics.boundingRect("_" * 81).width()
        height = metrics.lineSpacing()
        scroll_width = self.verticalScrollBar().width()
        size = QSize(width + scroll_width, height * 25)
        return size


class OutputView(QWidget):
    def __init__(self, parent=None, **kwargs):
        QWidget.__init__(self, parent, **kwargs)

        self.__lines = 5000

        self.setLayout(QVBoxLayout())
        self.layout().setContentsMargins(0, 0, 0, 0)

        self.__text = TerminalView()

        self.__currentCharFormat = self.__text.currentCharFormat()

        self.layout().addWidget(self.__text)

    def setMaximumLines(self, lines):
        """
        Set the maximum number of lines to keep displayed.
        """
        if self.__lines != lines:
            self.__lines = lines
            self.__text.setMaximumBlockCount(lines)

    def maximumLines(self):
        """
        Return the maximum number of lines in the display.
        """
        return self.__lines

    def clear(self):
        """
        Clear the displayed text.
        """
        self.__text.clear()

    def setCurrentCharFormat(self, charformat):
        """Set the QTextCharFormat to be used when writing.
        """
        if self.__currentCharFormat != charformat:
            self.__currentCharFormat = charformat

    def currentCharFormat(self):
        return self.__currentCharFormat

    def toPlainText(self):
        """
        Return the full contents of the output view.
        """
        return self.__text.toPlainText()

    # A file like interface.
    def write(self, string):
        self.__text.moveCursor(QTextCursor.End, QTextCursor.MoveAnchor)
        self.__text.setCurrentCharFormat(self.__currentCharFormat)

        self.__text.insertPlainText(string)

    def writelines(self, lines):
        self.write("".join(lines))

    def flush(self):
        pass

    def writeWithFormat(self, string, charformat):
        self.__text.moveCursor(QTextCursor.End, QTextCursor.MoveAnchor)
        self.__text.setCurrentCharFormat(charformat)
        self.__text.insertPlainText(string)

    def writelinesWithFormat(self, lines, charformat):
        self.writeWithFormat("".join(lines), charformat)

    def formated(self, color=None, background=None, weight=None,
                 italic=None, underline=None, font=None):
        """
        Return a formated file like object proxy.
        """
        charformat = update_char_format(
            self.currentCharFormat(), color, background, weight,
            italic, underline, font
        )
        return formater(self, charformat)


def update_char_format(baseformat, color=None, background=None, weight=None,
                       italic=None, underline=None, font=None):
    """
    Return a copy of `baseformat` :class:`QTextCharFormat` with
    updated color, weight, background and font properties.

    """
    charformat = QTextCharFormat(baseformat)

    if color is not None:
        charformat.setForeground(color)

    if background is not None:
        charformat.setBackground(background)

    if font is not None:
        charformat.setFont(font)
    else:
        font = update_font(baseformat.font(), weight, italic, underline)
        charformat.setFont(font)

    return charformat


def update_font(basefont, weight=None, italic=None, underline=None,
                pixelSize=None, pointSize=None):
    """
    Return a copy of `basefont` :class:`QFont` with updated properties.
    """
    font = QFont(basefont)

    if weight is not None:
        font.setWeight(weight)

    if italic is not None:
        font.setItalic(italic)

    if underline is not None:
        font.setUnderline(underline)

    if pixelSize is not None:
        font.setPixelSize(pixelSize)

    if pointSize is not None:
        font.setPointSize(pointSize)

    return font


class formater(object):
    def __init__(self, outputview, charformat):
        self.outputview = outputview
        self.charformat = charformat

    def write(self, string):
        self.outputview.writeWithFormat(string, self.charformat)

    def writelines(self, lines):
        self.outputview.writelines(lines, self.charformat)

    def flush(self):
        self.outputview.flush()

    def formated(self, color=None, background=None, weight=None,
                 italic=None, underline=None, font=None):
        charformat = update_char_format(self.charformat, color, background,
                                        weight, italic, underline, font)
        return formater(self.outputview, charformat)

    def __enter__(self):
        return self

    def __exit__(self, *args):
        self.outputview = None
        self.charformat = None


class TextStream(QObject):
    stream = Signal(str)
    flushed = Signal()

    def __init__(self, parent=None):
        QObject.__init__(self, parent)

    def write(self, string):
        self.stream.emit(string)

    def writelines(self, lines):
        self.stream.emit("".join(lines))

    def flush(self):
        self.flushed.emit()


class ExceptHook(QObject):
    handledException = Signal(object)

    def __init__(self, parent=None, stream=None, canvas=None, **kwargs):
        QObject.__init__(self, parent, **kwargs)
        self._stream = stream
        self._canvas = canvas

    def __call__(self, exc_type, exc_value, tb):
        if self._stream:
            header = exc_type.__name__ + ' Exception'
            if QThread.currentThread() != QCoreApplication.instance().thread():
                header += " (in non-GUI thread)"
            text = traceback.format_exception(exc_type, exc_value, tb)
            text.insert(0, '{:-^79}\n'.format(' ' + header + ' '))
            text.append('-' * 79 + '\n')
            self._stream.writelines(text)

        self.handledException.emit(((exc_type, exc_value, tb), self._canvas))
